ABSTRACT: OVERALL Significant hearing loss among older Americans exceeds 50%, suggesting that age-related hearing loss (ARHL) is one of the most common chronic health conditions experienced by older people. Untreated hearing loss is linked to depression, social isolation, and cognitive decline. While hearing aids remain the primary device for improving communication for those with ARHL, the take-up rate is relatively low at about 25%. Understanding speech in degraded listening situations (e.g., noise, reverberation, fast speech) continues to be a major challenge for older people, even among those with normal hearing. The underlying problem stems from limitations in the auditory periphery, the central auditory pathways, cognitive abilities, and alterations in the auditory-cognitive networks that support processing of auditory signals in noise and other forms of stimulus degradation. While a broad understanding of the problems experienced by older people is crystallizing, efforts to alleviate the problem through systematic investigation have been sparse. Thus, the over-arching goal of this Program Project Grant is to develop an integrative model of neuroplasticity in auditory aging, which will identify beneficial intervention strategies for mitigating the impact of auditory -cognitive decline with aging and will identify key loci of change in the auditory pathways that correlate with the most positive outcomes. The focus is on adaptive behavioral training to 1) enhance the auditory attention network to improve selective attention to relevant information and to suppress irrelevant information; 2) re-establish the appropriate balance between excitatory and inhibitory firing patterns to enhance auditory processing and cognition; and 3) improve neural timing to enhance precision of coding of acoustic stimuli to improve acoustic scene analysis and speech recognition. These targeted indices of positive neural plasticity will be monitored through a systems approach using behavior, electrophysiology, and imaging with humans and animals. The program includes 3 projects (P1: (Listening in noise, clutter, and reverberant environments ? central effects of aging and approaches to remediation; P2: Auditory temporal processing; P3: Speech Perception Training with High Cognitive Demand) and 3 cores (Core A: Administrative; Core B: Signal Processing and Data Analysis; Core C: Human Subjects Research Core), and involves 9 highly collaborative auditory and cognitive neuroscientists with a dedicated interest in solving the problems of speech communication with aging. If successful, the program has the potential to restore successful communication and improve quality of life for millions of older Americans.